<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <!--
     inline:行内元素
     block:块元素
     inline-block:即使行内元素也是块元素，保持块元素的特性、可以写在一行。
     none:消失，连同空间一块消失
     -->
    <style>
        div{
            width: 100px;
            height: 100px;
            border: 1px solid green;
            display: inline-block;
        }
        span{
            width: 100px;
            height: 100px;
            border: 1px solid green;
            display: inline-block;
        }
    </style>
</head>
<body>

<div>div块内元素</div>
<span>行内元素</span>

</body>
</html>